Semi-persistent relocatable ram-based virtual floppy disk method

ABSTRACT

The invention is a method and related structure for providing operating system drivers during installation of the operating system, where those operating system drivers are provided by way of a virtual disk drive. Basic input/output system (BIOS) routines are adapted to support showing these operating system drivers as residing on a virtual disk drive within the system. The operating system drivers are stored in the unreserved ROM space of the computer. Further, multiple floppy images are stored in the ROM, and the BIOS is adapted to show only the floppy image appropriate for the operating system to be installed. The virtual drive contents may be those operating system drivers stored in the unreserved ROM, but also may be physically stored in RAM.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to application Ser. No. 09/966,064 entitled“Reserved ROM Space for Storage of Operating System Drivers,” filed Sep.28, 2001. This application is also a divisional application ofapplication Ser. No. 09/965,998, now U.S. Pat. No. [NOT YET ASSIGNED]titled “Semi-Persistent Relocatable RAM-Based Virtual Floppy DiskMethod,” which application is incorporated by reference herein as ifreproduced in full below.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to loading operating systems oncomputer or server systems. More particularly, the preferred embodimentsof the present invention are directed to insuring the availability ofoperating system drivers during the operating system installationprocess. More particularly still, the preferred embodiments of thepresent invention are directed to storing operating system drivers inunreserved ROM and making those drivers available during theinstallation of the operating system.

2. Background of the Invention

One of the first functions that must be performed before a computer orserver system is ready for operation is installation of the operatingsystem. In early computer systems, this involved loading the DiskOperating System (DOS) to make available the then-familiar “C:>” prompt.For many years, DOS was the predominant operating system, even ifanother form of Graphical User Interface (GUI) was used. In recentyears, however, software companies such as Microsoft, Inc. have createdand are disseminating software that is not DOS-based. For example,Windows NT is an operating system and GUI in one package. Likewise,Windows 2000 is an operating system and GUI. These new systemscommunicate with hardware within the computer system by way of operatingsystem or hardware drivers, rather than through traditional basicinput/output system (BIOS) routines. During the process of installingthese operating systems/user interfaces, it is required that properdrivers are installed for the hardware resident in the computer system.

Although several software manufacturers make operating systems, e.g.,Linux, Novell, and Windows, the problem of installing correct operatingsystem drivers is inherent in each package. In particular, softwaremanufacturers typically bundle, along with the programs that make uptheir operating system, every operating system driver available as ofthe release date. However, there may be many months or even yearsbetween the release of the operating system and manufacture of thehardware devices within the computer system. Thus, it is inevitable thedrivers are needed that are not included with the operating system.Installing an operating system driver other than one of the driversincluded with the operating system software typically involves findingthe appropriate driver, either on the internet or on a CD ROM includedwith the computer system. This driver is then typically copied or“punched-out” to a floppy drive (on a second computer as the CD ROM onthe computer involved in the installation process is most likely notoperational). The floppy disk drive including the required operatingsystem driver is then inserted into the floppy drive unit of theaffected computer at the appropriate time during the installationprocess.

While it is possible to install the correct operating system driver inthis manner, it is seen from the above discussion that this is acomplicated procedure. In the context of installing the operating systemonto a server in a rack of servers, the situation gets more complex aseach individual server may not have its own floppy drive; but rather,keyboard, video and floppy drive access may only be available across acommunication bus.

Thus, what is needed in the art is a way to provide, during theoperating system installation, operating system drivers withoutrequiring the user to punch-out floppy disk drives or search theinternet via other computer devices to find the necessary drivers.

BRIEF SUMMARY OF THE INVENTION

The problems noted above are solved in large part by a semi-persistentrelocatable RAM-based virtual disk drive. In particular, operatingsystem drivers are provided in ROM space. Those drivers are madeavailable for copying during installation of the operating system byhaving the drivers appear to reside on a virtual floppy drive in thesystem.

In a second aspect of the preferred embodiments, multiple floppy imagesare preferably stored in the ROM space. Each of the floppy imagespreferably contains one or more operating system drivers for use with aparticular type of operating system. Prior to installation of theoperating system, the user preferably selects, by way of BIOS setupscreens, which operating system is to be installed on a particularcomputer or server system. This selection process preferably sets anenvironment variable within a non-volatile memory in the computersystem. BIOS routines, specifically interrupt 13h routines, preferablyaccess the environment variables as an indication of which floppy imageto provide in a virtual format such that operating system drivers may becopied at an appropriate time in the installation process.

In another aspect of the preferred embodiments, the virtual disk driveis provided at any location within the virtual address space. Thus, theactual contents of the virtual disk drive may reside on the ROM, whichis mapped in the virtual address space, but also may reside at any otherlocation within the virtual address space, for example within the RAMarea of the virtual address space. In this way, a virtual floppy drivehaving semi-persistent qualities may have its contents placed in theRAM. Such a virtual disk drive contents would survive a warm bootprocedure, such as that instituted by an interrupt 19h BIOS routine.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the preferred embodiments of theinvention, reference will now be made to the accompanying drawings inwhich:

FIG. 1 shows a computer system of the preferred embodiment;

FIG. 2 shows, in block diagram form, the contents of a ROM of the priorart;

FIG. 3 shows, in block diagram form, the contents of a ROM of one of theembodiments of the present invention;

FIG. 4 shows, in block diagram form, the contents of a ROM of oneembodiment of the present invention;

FIG. 5 shows, in block diagram form, the contents of a ROM of oneembodiment of the invention, both before and after copying of theoperating system drivers;

FIG. 6 shows, in block diagram form, the contents of a ROM of oneembodiment of the invention having multiple floppy images containedthereon; and

FIG. 7 shows a virtual memory map of the preferred embodiments.

NOTATION AND NOMENCLATURE

Certain terms are used throughout the following description and claimsto refer to particular system components. As one skilled in the art willappreciate, computer companies may refer to a component by differentnames. This document does not intend to distinguish between componentsthat differ in name but not function.

In the following discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to . . . ”. Also, theterm “couple” or “couples” is intended to mean either an indirect ordirect electrical connection. Thus, if a first device couples to asecond device, that connection may be through a direct electricalconnection, or through an indirect electrical connection via otherdevices and connections.

Throughout the specification and claims, the term read only memory (ROM)refers to integrated circuit memory devices. If other types of read onlymemory devices are the focus of the discussion, those will be referredto directly, e.g., compact disk ROM (CDROM) and the like. Thus, the termROM, unless specifically limited, may mean programmable read only memory(PROM), erasable programmable read only memory (EPROM), and the variantsof EPROM such as ultra-violet erasable programmable read only memory(UVPROM) and electrically erasable programmable read only memory(EEPROM).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, computer system 100 in accordance with thepreferred embodiment comprises at least one CPU 10. Inasmuch as computersystem 100 is preferably a server system, the computer system 100 maycomprise multiple CPUs 10A, 10B, 10C, 10D arranged in a configurationwhere parallel computing may take place. The CPU array 10 couples to amain memory array 12 and a variety of other peripheral computer systemcomponents through an integrated host bridge logic device 14. The CPUarray 10 may comprise, for example, a plurality of Pentium® IIImicroprocessors. It should be understood, however, that computer system100 could include other alternative types and numbers ofmicroprocessors. Additionally, other architectures could be used ifdesired. Thus, the computer system may implement other busconfigurations and bus bridges in addition to, or in place of, thoseshown in FIG. 1.

The main memory array 12 preferably couples to the host bridge logic 14through a memory bus 16, and the host bridge logic 14 preferablyincludes a memory control unit (not shown) that controls transactions tothe main memory 12 by asserting the necessary control signals duringmemory accesses. The main memory 12 functions as the working memory forthe CPUs 10 and generally includes a conventional memory device or arrayof memory devices in which program instructions and data are stored. Themain memory array 12 may comprise any suitable type of memory such asDynamic Random Access Memory (DRAM) or any of the various types of DRAMdevices such as Synchronous DRAM (SDRAM), Extended Data Output DRAM (EDODRAM), or Rambus™ DRAM (RDRAM).

Inasmuch as computer system 100 is preferably a server system, thecomputer system 100 may not have a dedicated display device. If thecomputer system did have a dedicated display device, such a system couldbe implemented by coupling a video driver card to the host bridge 14 byway of an Advanced Graphics Port bus or other suitable type of bus.Alternatively, the video driver card could couple to the primaryexpansion bus 18 or one of the secondary expansion buses, for example,the PCI bus 20. If the computer system had a dedicated display device,the video driver or graphic controller would couple to a display device.That display may comprise any suitable electronic display device uponwhich any image or text can be represented.

The computer system 100 preferably comprises a second bridge logicdevice 22 that bridges the primary expansion bus 18 to various secondarybuses including a low pin count (LPC) bus 24 and a peripheral componentinterconnect (PCI) bus 20. In accordance with the preferred embodiment,the bridge device 36 is an Input/Output Controller Hub (ICH)manufactured by Intel Corporation. Although the ICH 22 of FIG. 1 isshown only to support the LPC bus 24 and the PCI bus 20, various othersecondary buses may be supported by the ICH 22. In the preferredembodiment shown in FIG. 1, the primary expansion bus 18 comprises aHub-link bus which is a proprietary bus of the Intel Corporation.However, computer system 100 is not limited to any particular type ofprimary expansion bus, and thus other suitable buses may be used.

Referring still to FIG. 1, a firmware hub 26 couples to the ICH 22 byway of the LPC bus 24. The firmware hub 26 preferably comprises ReadOnly Memory (ROM) which contains software programs executable by the CPUarray 10. The software programs preferably include programs to implementbasic input/output system (BIOS) commands, and instructions executedduring and just after Power On Self Test (POST) procedures.

A Super Input/Output controller 28 couples to the ICH 22 and controlsmany system functions including interfacing with various input andoutput devices such as keyboard 30. The Super I/O controller 28 mayfurther interface, for example, with a system pointing device such as amouse 32, various serial ports (not shown) and floppy drives (notshown). The Super I/O controller is often referred to as “super” becauseof the many I/O functions it may perform.

Also shown in the computer system 100 of FIG. 1 are three arraycontrollers 50A, 50B, 50C coupled to the ICH 22 by way of the PCI bus20. Each array controller 50 couples to a plurality of hard drives 52A,52B, 52C. Thus, the array controller 50 preferably performs data reads,data writes and other necessary data manipulation to implement aredundant array of independent devices (RAID) system. It will beunderstood that while FIG. 1 shows only three array controllers 50,computer system 100 may support any number of these controllers. It mustbe understood however that the invention is not limited to computersystems having multiple CPUs or implementing RAID systems; rather, thepreferred embodiments apply equally to all types of computer systems.

The preferred embodiments of the present invention address how toprovide operating system drivers during the operating systeminstallation process. In particular, the preferred embodiments of thepresent invention provide necessary operating system drivers by placingor storing those drivers in the ROM or firmware hub 26. Preferably,required or needed operating system drivers may simply be copied fromthose versions resident in the system ROM 26 during the operating systeminstallation procedure.

In computer systems requiring high availability and reliability, e.g.,server systems, it is common to have multiple copies of the BIOSfirmware or programs stored in the system ROM 26. FIG. 2 shows a priorart technique for having multiple copies that simply involves burningtwo copies of the BIOS programs onto the ROM 26. In particular, FIG. 2shows two copies of the BIOS, with the first copy occupying the first512 kilobytes of the ROM, and the second copy occupying the second 512kilobytes of the one megabyte ROM. As one of ordinary skill in the artis aware, most computer and server systems have a smaller ROM known as a“boot-block” ROM (not shown) that is responsible for selecting which ofthe multiple copies of the BIOS will be loaded during the POSTprocedure.

Placing operating system drivers in the ROM 26 may take many forms. FIG.3 shows one embodiment in which the operating system drivers (labeledOSD in the drawing) are placed within each redundant section of the ROM26. At the appropriate time during the operating system installationprocedure, either or both of the drivers stored on the ROM 26 would bemade available for copying and use by the operating system. A preferredembodiment for making those operating system drivers available isdiscussed more fully below.

Operating system drivers range in complexity, and therefore range insize, with some drivers approaching 100 kilobytes or more. In asituation where the drivers are large, the implementation shown in FIG.3 would not be desirable inasmuch as the operating system drivers wouldoccupy significant space in the ROM (especially given the duplication).Conversely, if the operating system drivers to be provided on the ROM 26are relative small, the implementation exemplified in FIG. 3 may beacceptable.

Where the operating system drivers are large, or a number of driversmust be provided, the preferred embodiments provide for storing thoseoperating system drivers in a non-redundant area of the ROM 26. FIG. 4shows an implementation where a larger, preferably two megabyte, ROM isused. Preferably, the ROM is divided up into redundant 30 andnon-redundant 32 space. In FIG. 4, the redundant space is shown tooccupy the first one megabyte of the ROM 26, and the non-redundantspace, containing the operating system drivers, is shown to occupy thesecond one megabyte. It must be understood, however, that division ofthe ROM 26 of FIG. 4 is only exemplary, and the storage space of the ROM26 may be divided in any convenient way. Using the implementationexemplified in FIG. 4, a boot-block program stored on a boot-block ROM(not shown), selects one of the two BIOS firmware copies stored in theredundant area 30 of the ROM 26. Thereafter, and at the appropriate timeduring the operating system installation procedure, the operating systemdrivers located in the non-redundant area 32 of the ROM are madeavailable.

In the exemplary implementation of storing operating system drivers onthe ROM 26 as shown in FIG. 4, the size of the ROM 26 was increased fromone megabyte to two megabytes, such that the duplicate copies of theBIOS and the operating system drivers could reside on a single ROMdevice. However, increasing the size of the ROM 26 also increases systemcost. For this reason, some manufacturers may not want to spend theadditional money to provide the larger ROMs, but still may want toprovide redundant copies of the BIOS and also provide copies of theoperating system drivers on the ROM.

FIG. 5 shows one possible implementation for providing both theredundant BIOS and the operating system drivers on the ROM. Inparticular, the upper ROM 26 is shown to have a single copy of the BIOSprograms, as well as a copy of the operating system drivers. Preferably,the ROM 26 has this configuration as it leaves the factory and duringthe operating system installation procedure. The program stored in theboot block ROM (not shown) determines whether the ROM contents are BIOSprograms or operating system drivers by use of signatures in the BIOSfirmware that identify the programs. Preferably, once the operatingsystem drivers have been provided during installation of the operatingsystem, a utility program copies the BIOS, provided only innon-redundant fashion initially, to the second half of the ROM 26. Bycopying the BIOS over the operating system drivers, a redundant BIOSsystem is provided, as shown in the lower ROM 26 of FIG. 5. While thisimplementation provides both the redundant BIOS, after operating systeminstallation, and also provides operating system drivers on the ROM, theoperating system drivers are overwritten and thus will not be availableif the operating system must be installed again.

While there may be many ways to implement making the operating systemdrivers stored on the ROM 26 available during the operating systeminstallation procedure, the Applicants now endeavor to describe thepreferred method. Making the operating system drivers available hasthree aspects in the preferred embodiment: 1) providing the latestdrivers for each major operating system; 2) making those driversavailable to the user during installation of the operating system by useof a virtual disk drive; and 3) providing those operating system driversin a virtual drive scheme with the system drivers residing in RAM.

As discussed in the Background section, there are many availableoperating systems for computers in the marketplace, e.g., Linux(manufactured by Red Hat Software), Novell (manufactured by NovellIncorporated), Windows 2000 (manufactured by Microsoft Inc.). For aparticular piece of hardware in the system, e.g., an array controller 50(FIG. 1), each operating system may require a different driver. This maybe due in part to differences in protocols with regard to interfacingwith the operating system, but may also be caused merely by differencesin file structures between operating systems. Stated otherwise, a driverfor operating an array controller 50 in a Windows 2000 environment (FATfile system) may not be suitable for use in a Linux environment (2×72file system). Thus, in the preferred embodiment, if drivers need to beincluded on the system ROM 26, preferably drivers for each of the majoroperating systems are provided. Considering that there may be an arrayof devices for which the latest operating system driver may be provided,it is easily seen that the amount of space on the ROM 26 required tostore each driver for each hardware system may become rather large. Inthis regard, the implementation shown in FIG. 4 for dividing the ROM 26into a redundant 30 and non-redundant 32 portion is the preferredimplementation.

FIG. 6 exemplifies the situation where multiple sets of operating systemdrivers are provided. In particular, FIG. 6 shows that the non-redundant32 space of the ROM 26 contains several sets of drivers, in theexemplary system, a set of Linux drivers 34, Novell drivers 36 andWindows drivers 38. It must be understood that providing theseparticular drivers is only exemplary, and any number of drivers for anynumber of operating systems may be provided and still be within thecontemplation of this invention. Further, FIG. 6 implies that theoperating system drivers occupy the entire non-redundant 32 space of theROM 26; however, this need not necessarily be the case, and any or allof the non-redundant 32 space may be used to store the operating systemdrivers.

In the preferred embodiment described above, a set of operating systemdrivers (34, 36, 38 of FIG. 6), which may alternatively be referred toas floppy images, are provided in the ROM 26. These multiple sets ofoperating system drivers are provided to account for the fact that amanufacturer may not know at the time of building the computer systemwhat operating system will be installed thereon. Since multiple sets ofoperating system drivers are preferably provided, there should be amethod of providing the correct drivers for the particular operatingsystem. In the preferred embodiments, making available the correctoperating system drivers for the operating system is preferablyaccomplished by a BIOS setup parameter and a modification to thestandard disk access routine known as Interrupt 13h.

In the preferred embodiment the BIOS setup routines are modified tocontain a field where a user, when making an initial setup of the BIOS,selects which operating system is to be installed on the computer orserver. It must be understood that this selection in the BIOS is not apart of the operating system installation procedure; but rather, ismerely a mechanism to inform the BIOS which operating system is to beinstalled. Preferably, the BIOS uses this information to select anappropriate floppy image having a set of operating system drivers fromthe images stored in the non-redundant 32 space of the ROM 26. Forexample, if a user selects from the BIOS setup screen that Windows 2000will be the operating system for the computer, the BIOS then makesavailable, in a manner described more fully below, the floppy imagecontaining Windows operating system drivers 38 (see FIG. 6).

While there may be many ways to make the particular operating systemdrivers available during the operating system installation process, inthe preferred embodiments, those drivers are made available to the userand to the operating system installation procedure by having them resideon a virtual floppy drive or virtual disk drive. More particular, in thepreferred embodiment, the Interrupt 13h BIOS calls for performing diskdrive activities are preferably implemented such that the operatingsystem drivers (either all of them or just the appropriate drivers forthe particular operating system) stored on the ROM 26 appear to resideon a disk drive. Because the files are not actually stored on a floppydisk, this is known as creating a virtual drive. As mentioned above, theuser preferably selects in a BIOS setup screen which operating system isto be installed on the computer system, and based on that selection,preferably only the drivers appropriate for the selected operatingsystem are made available in this virtual drive method. One of ordinaryskill in the art is familiar with Interrupt 13h BIOS calls, how toimplement them, and now understanding how to provide drivers in thisway, could modify the standard programs to provide this virtual drivefeature.

More particularly still, in the preferred embodiment, selecting aparticular operating system to be installed preferably sets anenvironment variable in a non-volatile memory. This non-volatile memorycould be non-volatile RAM (NVRAM), or may be written directly to the ROM26, which in the preferred embodiment is electrically erasableprogrammable read only memory (EEPROM). Regardless of the location ofthe environment variables, by selecting an operating system, theenvironment variables preferably point to a floppy image havingoperating system drivers appropriate for that operating system. Duringthe installation process, before the operating system is installed, diskservices are provided by the BIOS. Thus, during installation, theInterrupt 13h services preferably are adapted to show the appropriateoperating system drivers, indicated by the environment variables, asresiding on a disk drive. Thus, drivers needed for correct setup duringthe operating system installation process are then available as if theyhad been copied to a floppy and inserted in a disk drive in the system.Using the preferred embodiment alone, it is then possible to provide theoperating system drivers during the operation system installationprocess by informing the installation program of the need to use driversdifferent than those provided with the operating system, and pointingthat operating system software to the virtual drive. However, nowunderstanding how to make available software drivers in the manner ofthe preferred embodiment, one of ordinary skill in the art could easilymodify the installation program to automatically search for and usedrivers resident on virtual drives with little or not user input.

Referring now to FIG. 7, there is shown an exemplary virtual addressspace or virtual memory map for the computer or server system of thepreferred embodiment. As one of ordinary skill in the art is aware, theROM 26 contents are typically mapped in the virtual address space to alocation having addresses just below the four gigabyte addressablespace. In this way, the system devices wishing to access the ROMcontents need only know the addresses of those ROM contents in thevirtual address space. As exemplified in FIG. 7, the virtual addressspace includes not only the floppy images having the operating systemdrivers 34, 36 and 38, but also includes all the addressable space forthe random access memory (RAM), the RAM area. Thus, in the preferredembodiment, when the user selects the particular operating system to beinstalled in the BIOS setup screens, the BIOS preferably updates anenvironment variable which points, in the virtual address space, to theoperating system drivers appropriate for that operating system to beinstalled. Sometime thereafter, when performing disk accesses using theBIOS subroutines, the installation process requests an operating systemdriver from a virtual drive. The Interrupt 13h services provide theoperating system drivers available at the location indicated by theenvironment variables as if those drivers were provided on an actualfloppy drive.

It is noted, however, that the mapping of the possible operating systemdrivers 34, 36 and 38 are within the same virtual address space as therandom access memory (FIG. 7). In another aspect of the invention,information and data may be provided to the operating system by use of avirtual disk drive, where the contents of that virtual disk driveresides in the RAM area 62 portion of the virtual memory rather than oneof the operating system drivers, again within the virtual address space.Data and programs placed in a virtual drive with its contents stored inRAM would be semi-persistent, meaning that the data would survive and beavailable after a warm boot, for example an warm boot initiated by anInterrupt 19h.

While creating a virtual disk drive resident in RAM and accessiblethrough BIOS interrupts was developed in the context of providingoperating system drivers during operating system installationprocedures, any data or programs which need to be made available in asemi-persistent manner may be provided in this way, and still be withinthe contemplation of the invention.

The above discussion is meant to be illustrative of the principles andvarious embodiments of the present invention. Numerous variations andmodifications will become apparent to those skilled in the art once theabove disclosure is fully appreciated. For example, the preferredembodiments have been described with regard to placing the operatingsystem drivers on the same ROM as the BIOS programs; however, the ROMprovided in the computer system could be a ROM array comprising severalindividual ROM devices, and the operating system software could resideon any or all of the ROM devices, and still be within the contemplationof this invention. Further, providing operating system drivers in themanner described herein was developed in the context of server systemshaving multiple microprocessors and multiple hard drives implementingRAID systems; however, one of ordinary skill in the art, nowunderstanding how to implement and use the preferred embodiments, couldeasily apply the preferred embodiments to stand alone computer systemshaving only a single microprocessor and single hard drive. Further, thesystems and methods described herein are equally applicable to mostcomputing devices such as hand-held computing devices, portablecomputers, process control systems, and the like. It is intended thatthe following claims be interpreted to embrace all such variations andmodifications.

1. A method comprising: storing the operating system drivers on a readonly memory (ROM) within the computer system; and copying at least oneof the operating system drivers from a virtual disk drive of thecomputer system during the operating system installation.
 2. The methodas defined in claim 1 wherein storing the operating system drivers onthe ROM within the computer system further comprises storing theoperating system drivers on the ROM along with a basic input outputsystem (BIOS).
 3. The method as defined in claim 1 wherein storingoperating system drivers on the ROM within the computer furthercomprises: storing on the ROM a first set of operating system driversoperable with a first operating system; and storing on the ROM a secondset of operating system drivers operable with a second operating system.4. The method as defined in claim 3 further comprising having onlyoperating system drivers operable with the operating system to beinstalled available for copying from the virtual disk drive.
 5. Acomputer system comprising: a CPU; a main memory array coupled to theCPU; an expansion bus coupled to the CPU; a read only memory (ROM) arraycoupled to the secondary expansion bus, the ROM array stores operatingsystem drivers; and the computer system is configured to make theoperating system drivers appear to reside on a virtual floppy drive forcopying during loading of an operating system for the computer system.6. The computer system as defined in claim 5 wherein the ROM array alsostores basic input output system (BIOS) firmware.
 7. The computer systemas defined in claim 6 wherein the BIOS firmware, when invoked for diskservices, is adapted to make the operating system drivers appear toreside on the virtual floppy drive.
 8. The computer system as defined inclaim 5 further comprising: said ROM array stores a first set ofoperating system drivers for a first operating system; said ROM arraystores a second set of operating system drivers for a second operatingsystem; and the computer system is configured to make only one of thefirst and second set of operating system drivers available for copyingfrom the virtual floppy drive during loading of the operating system forthe computer system.
 9. A method comprising: storing operating systemdrivers on a read only memory (ROM); informing a basic input outputsystem (BIOS) of an operating system type to be installed; makingavailable during the loading of the operating system the operatingsystem drivers stored on the ROM appropriate for the operating systemtype to be installed; installing the operating system; and copying atthe appropriate time during the installing of the operating system atleast on of the operating system drivers from a virtual floppy drive.10. The method as defined in claim 9 wherein storing operating systemdrivers on the ROM further comprises: storing a first set of operatingsystem drivers operable with a first operating system; and storing asecond set of operating system drivers operable with a second operatingsystem.
 11. The method as defined in claim 9 wherein informing the BIOSof the operating system type to be installed further comprises:selecting the operating system type to be installed on a BIOS setupscreen; and setting an environment variable in a non-volatile randomaccess memory (RAM) based on the selecting step that indicates theoperating system type to be installed.
 12. The method as defined inclaim 11 wherein making available the operating system drivers stored onthe ROM further comprises: using BIOS programs to access the operatingsystem drivers stored on the ROM; referring, by the BIOS programs, tothe environment variable in non-volatile RAM; and making one of thefirst and second set of operating system drivers available on thevirtual floppy drive by the BIOS program based on a state of theenvironment variable in non-volatile RAM.
 13. A method of providingoperating system drivers during an operating system installation on acomputer system, the method comprising: storing a first set of operatingsystem drivers operable with a first operating system in a read onlymemory (ROM) of the computer system; storing a second set operatingsystem drivers operable with a second operating system in the ROM; andcopying at least one of the operating system drivers from a virtual diskdrive of the computer system during the operating system installation.14. The method of providing operating system drivers as defined in claim13 further comprising: selecting on a basic input output system (BIOS)setup screen one of the first and second sets of operating systems, aselected system, to be installed on the computer system; and having onlyoperating system drivers operable with selected system, selecteddrivers, available for copying from the virtual drive.
 15. The method ofproviding operating system drivers as defined in claim 14 furthercomprising: requesting disk services to a disk drive name that does notphysically reside in the computer system by; invoking interrupt 13h BIOSservices directed to the disk drive name that does not physically residein the computer system; and returning file names for the selecteddrivers by the interrupt 13h BIOS services as if the selected driversresided on the disk drive name that does not physically reside in thecomputer system.
 16. A method of providing operating system driversduring an operating system installation on a computer system, the methodcomprising: storing a first floppy image having a first set of operatingsystem drivers operable with a first operating system, the first floppyimage stored in a read only memory (ROM) of the computer system; storinga second floppy image having a second set of operating system driversoperable with a second operating system, the second floppy image storedin the ROM; and providing one of the first and second floppy images as avirtual floppy drive during the operating system installation.
 17. Themethod of providing operating system drivers as defined in claim 16further comprising: selecting on a basic input output system (BIOS)setup screen one of the first and second sets of operating systems, aselected system, to be installed on the computer system; and having onlythe floppy image having operating system drivers operable with selectedsystem, a selected floppy image, available on the virtual floppy drive.18. The method of providing operating system drivers as defined in claim17 wherein providing one of the first and second floppy images as avirtual floppy drive during the operating system installation furthercomprising: requesting disk services to a disk drive name that does notphysically reside in the computer system by; invoking interrupt 13h BIOSservices directed to the disk drive name that does not physically residein the computer system; and returning file names in the selected floppyimage by the interrupt 13h BIOS services as if the selected floppy imageresided on the disk drive name that does not physically reside in thecomputer system.